South Korean President Park Geun-hye looks at Japanese Prime Minister Shinzo Abe (L) while speaking at a news conference after a trilateral summit at the Presidential Blue House in SeoulReuters

Japan and South Korea have pledged to find common ground and resolve issues such as "comfort women" that have for decades marred ties between the East Asian neighbours. The resolve came at a trilateral meet of the two countries and China, with all three saying they had "completely restored" trade and security ties, and would increasingly cooperate with one another.

"It's the 50th anniversary of the normalisation of (Japan-South Korea) ties this year. Keeping that in mind, we've agreed to accelerate talks for the earliest possible resolution. Regarding the issue of 'comfort women', I believe we should not leave behind difficulties for future generations as we try to build a future-oriented cooperative relationship," Japanese Prime Minister Shinzo Abe said at the summit.

The issue of "comfort women" or sex slaves during Japan's colonisation of Korea during 1910-1945 has been a major obstacle to better ties between Washington's two key allies. According to war historians, tens of thousands of women from around Asia, many of them Korean, were sent to front-line military brothels to provide sex to Japanese soldiers.

"I hope today's summit will heal the bitter history in a broad sense and be a sincere one and an important opportunity to develop the two countries's relationship," South Korean President Park Geun-hye told Abe at the start of the talks, the first formal meeting between the two since Abe took office in 2012.

Bone of contention

Although the Japanese government has over time apologised for using "comfort women", South Korea feels its apology has not been sincere. It has accused Japanese leaders of repeatedly failing to atone for the war atrocities.

In 1993, Tokyo issued an apology called the Kono statement that acknowledged the Japanese military used coercion in operating the brothel system but did not admit the government's complicity. Many in the political class, including Abe, continued to cast doubt on the Kono statement, claiming the brothels were staffed by professional prostitutes. In fact, Abe has been criticised for his flip-flop on the issue. Many Japanese conservatives also say there is no proof that authorities directly coerced the women.

South Korea, however, says it wants the issue to be resolved in a way acceptable to victims and other South Koreans, and not just Japan. Japan offered to compensate former comfort women through a private fund set up in 1995 that operated until 2007. But many survivors shunned the cash as it did not come directly from the Japanese government. South Korea also rejected the fund.

The 1 November trilateral summit also focused on economic ties with China, in particular, keen to strengthen trade links to boost declining exports. The leaders also discussed the potential threat caused by North Korea's nuclear capability in wake of reports that the dictatorship planned to conduct its fourth nuclear test.

The three countries began holding annual summits in 2008.But the meetings were suspended since 2012 as Japan's relations with its two neighbours soured over World War II issues.